The structure, chemical reactions, and chemical characterization of the DPN ring opening products resulting from nucleophilic reactions with hydroxide ion and amines is to be investigated. The rate, molecularity, pH dependence, reagent dependence, and solvent dependence of the reversible amine-DPN reaction is to be investigated in order to determine whether these reactions represent the formation of charge transfer complexes or of covalent addition complexes. The pH and buffer dependence and reversibiltity of the acid modification reactions of DPNH and its analogues is to be investigated as well as the possibility of nonenzymatic oxidative phosphorylation by the oxidation of the acid modifications of DPNH and DPNH analogues. The structure of the secondary DPNH acid modification product and the pH and buffer dependence of its formation is to be determined. The structures of the primary acid modification product and of DPNH-X are to be compared.